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纳米SiC颗粒对镁合金搅拌摩擦焊接头性能影响研究
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作者 高辉 张楷 +1 位作者 林渊浩 雷丹 《制造技术与机床》 北大核心 2024年第3期108-114,共7页
为提高AZ31镁合金焊接接头的综合性能,文章分别研究了无纳米SiC-1道次、添加纳米SiC-1道次和SiC-4道次的搅拌摩擦焊焊接接头,通过光学显微镜、显微硬度仪和拉伸试验机分析了焊接接头的微观组织与力学性能;利用电化学工作站研究了接头的... 为提高AZ31镁合金焊接接头的综合性能,文章分别研究了无纳米SiC-1道次、添加纳米SiC-1道次和SiC-4道次的搅拌摩擦焊焊接接头,通过光学显微镜、显微硬度仪和拉伸试验机分析了焊接接头的微观组织与力学性能;利用电化学工作站研究了接头的腐蚀行为,采用扫描电镜、EDS和XRD分析了接头的腐蚀形貌、元素成分和物相组成。结果表明,搅拌摩擦焊焊接接头成形良好、无缺陷;接头焊核区组织为均匀的等轴状晶粒,焊接道次的增加可有效改善SiC颗粒的分布情况,异质形核位点的存在起到了晶粒细化的作用,提高了接头的力学性能;在3.5%NaCl溶液腐蚀试验中,含SiC颗粒的接头耐腐蚀性能提升,其中SiC-4道次的接头耐腐蚀性能最佳。 展开更多
关键词 纳米sic 搅拌摩擦焊 微观组织 力学性能 电化学腐蚀
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激光功率对PLC控制的SLM成形SiC增强铝基复合材料组织与性能的影响
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作者 张大俊 宋黎明 +1 位作者 李恒 邢峰 《精密成形工程》 北大核心 2024年第6期92-99,共8页
目的提升激光选区熔化成形(SLM)SiC增强铝基复合材料的力学性能。方法以球形纳米SiC和类球形AlSi10Mg粉末为原料,采用球磨工艺和基于PLC控制的SLM技术制备了SiC增强铝基复合材料(SiC/AlSi10Mg),考察了激光功率对复合材料物相、显微组织... 目的提升激光选区熔化成形(SLM)SiC增强铝基复合材料的力学性能。方法以球形纳米SiC和类球形AlSi10Mg粉末为原料,采用球磨工艺和基于PLC控制的SLM技术制备了SiC增强铝基复合材料(SiC/AlSi10Mg),考察了激光功率对复合材料物相、显微组织和力学性能的影响。结果复合粉末和激光功率为120~240 W的复合材料都主要含Al相和Si相;随着激光功率的增大,Al相择优结晶取向由(111)晶面转变到(200)晶面,在较高激光功率下,SLM成形试样中SiC熔化并与基体材料发生反应形成了Al4SiC4、Al4C3碳化物。在不同激光功率的SLM成形复合材料中都可见暗黑色α-Al基体和灰白色Al-Si共晶;随着激光功率增至210 W,Al-Si共晶组织逐渐碎片化并演变为网状,平均晶粒尺寸和小角度晶界体积分数逐渐增大。当激光功率从150 W增至240 W时,复合材料的纳米硬度和弹性模量先增后减,压缩强度逐渐减小,抗拉强度逐渐增大、断后伸长率先减后增而后又减小。结论当激光功率为210 W时,SiC增强铝基复合材料具有良好的综合力学性能,这主要与组织均匀化、晶粒细化以及碳化物/基体界面结合改善等有关。 展开更多
关键词 球形纳米sic AlSi10Mg 激光选区熔化成形 显微组织 力学性能
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ZrC纳米粉体改性C/C-SiC复合材料的微观结构和烧蚀性能
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作者 汤磊 白凯伦 +3 位作者 熊翔 尹健 张红波 左劲旅 《粉末冶金材料科学与工程》 2024年第3期191-200,共10页
为改善C/C-SiC复合材料的抗烧蚀性能,以ZrC纳米粉体和Si粉为反应渗料,采用反应熔渗(reactive melt infiltration,RMI)法制备ZrC纳米粉体改性C/C-SiC复合材料。采用X射线衍射仪、扫描电镜和能谱仪等研究ZrC纳米粉体含量对C/C-SiC复合材... 为改善C/C-SiC复合材料的抗烧蚀性能,以ZrC纳米粉体和Si粉为反应渗料,采用反应熔渗(reactive melt infiltration,RMI)法制备ZrC纳米粉体改性C/C-SiC复合材料。采用X射线衍射仪、扫描电镜和能谱仪等研究ZrC纳米粉体含量对C/C-SiC复合材料微观结构和烧蚀性能的影响。结果表明:随ZrC纳米粉体含量增加,复合材料的孔隙率增大,而密度变化不大。ZrC纳米粉体一部分弥散分布在SiC基体中,一部分则发生了团聚。烧蚀30 s后,ZrC纳米粉体摩尔分数为6%时,复合材料的质量烧蚀率和线烧蚀率最低,分别为2.0 mg/s和3.9μm/s。随ZrC纳米粉体含量增加,烧蚀过程中形成的ZrO_(2)含量增多,对SiO_(2)的钉扎作用明显增强,能有效提升C/C-SiC复合材料的抗烧蚀性能。 展开更多
关键词 C/C-sic复合材料 ZrC纳米粉体 反应熔渗 微观结构 烧蚀性能
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Ni-P/纳米SiC复合镀层制备及性能研究
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作者 郭明忠 谭世光 +1 位作者 任爽 马宇驰 《广州化工》 CAS 2024年第2期97-98,105,共3页
以45钢为基体材料,在其表面制备了Ni-P/纳米SiC复合镀层,研究了复合镀层的微观结构及热处理性能。结果表明:Ni-P/纳米SiC复合镀层由细小的胞状物构成,胞状物均匀致密,完全包覆于基体表面,复合镀层表面未见孔洞等缺陷。镀层由Ni、P、Si、... 以45钢为基体材料,在其表面制备了Ni-P/纳米SiC复合镀层,研究了复合镀层的微观结构及热处理性能。结果表明:Ni-P/纳米SiC复合镀层由细小的胞状物构成,胞状物均匀致密,完全包覆于基体表面,复合镀层表面未见孔洞等缺陷。镀层由Ni、P、Si、C等元素构成,弥散分布Si元素、C元素来自镀层中SiC粒子。热处理后,复合镀层显微硬度、耐腐蚀性优于热处理前的复合镀层。 展开更多
关键词 Ni-P/纳米sic复合镀层 热处理 显微硬度 耐腐蚀性
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CE/nano-SiC复合材料的制备及其改性研究 被引量:2
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作者 张文根 张学英 《中国胶粘剂》 CAS 北大核心 2014年第5期42-45,共4页
采用模塑成型法制备了CE(氰酸酯)/nano-SiC复合材料,通过弯曲强度测定、TGA(热失重分析)法和DMA(动态力学分析)法对复合材料的性能进行了分析。研究结果表明:nano-SiC经硅烷偶联剂(SCA-3)表面处理后,对复合材料的力学性能和耐热性具有... 采用模塑成型法制备了CE(氰酸酯)/nano-SiC复合材料,通过弯曲强度测定、TGA(热失重分析)法和DMA(动态力学分析)法对复合材料的性能进行了分析。研究结果表明:nano-SiC经硅烷偶联剂(SCA-3)表面处理后,对复合材料的力学性能和耐热性具有明显的协同改性作用;当w(nano-SiC)=1%(相对纯CE质量而言)时,nano-SiC经SCA-3表面处理前后,相应复合材料的弯曲强度分别提高了20.84%和32.84%,玻璃化转变温度分别提高了13.09%和18.29%,失重5%时的热分解温度分别提高了12.31%和13.87%,450℃时的质量保持率分别提高了26.24%和42.99%。 展开更多
关键词 氰酸酯 nanosic 硅烷偶联剂 复合材料 改性
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丝网印刷nano-SiC薄膜阴极的电子特性的研究 被引量:3
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作者 张秀霞 雷崇民 +3 位作者 王晓娥 盛洪江 魏舒怡 魏杰 《功能材料》 EI CAS CSCD 北大核心 2010年第4期555-557,561,共4页
研究了低成本大面积丝网印刷在玻璃衬底上均匀的纳米碳化硅(nano-SiC)薄膜的场致发射特性。提出了机械分散团聚的nano-SiC的方法,实验了适合导电玻璃衬底上制备nano-SiC薄膜的浆料配方,摸索导电玻璃衬底上nano-SiC薄膜的烧结工艺,研究... 研究了低成本大面积丝网印刷在玻璃衬底上均匀的纳米碳化硅(nano-SiC)薄膜的场致发射特性。提出了机械分散团聚的nano-SiC的方法,实验了适合导电玻璃衬底上制备nano-SiC薄膜的浆料配方,摸索导电玻璃衬底上nano-SiC薄膜的烧结工艺,研究了不同nano-SiC含量的薄膜的场发射特性,得到了最佳场致发射特性的配方比例。对样品进行微观分析和表征。具有稳定均匀场致发射性能的nano-SiC薄膜可作为显示器器件的阴极材料。 展开更多
关键词 纳米碳化硅薄膜 电子场发射 丝网印刷 后处理过程
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退火处理对Nano-SiC-Al_2O_3/TiC纳米陶瓷复合材料性能的影响 被引量:4
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作者 仝建峰 陈大明 蔡万华 《金属热处理》 CAS CSCD 北大核心 1999年第11期26-27,共2页
研究了退火工艺对纳米陶瓷复合材料力学性能的影响。研究表明,纳米陶瓷复合材料在适当退火工艺下,其抗弯强度和硬度可以提高40% ~50 % ,但断裂韧度略有下降。
关键词 纳米碳化硅 氧化铝 碳化钛 复合材料 退火处理
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Nano-SiC薄膜在太阳能电池窗口表面的应用 被引量:3
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作者 王二垒 张秀霞 +2 位作者 张丽霞 陈旭涛 杨小聪 《科学技术与工程》 北大核心 2013年第17期4878-4880,4889,共4页
由于环境的污染使空气中有泥土,太阳能电池在户外使用一段时间后,其窗口表面就会附着一些灰尘颗粒影响其进光量,进而影响太阳能电池的光电转换效率。采用溶胶凝胶法制备并通过热烧结过程,将Nano-SiC透明薄膜制备在太阳能电池窗口表面。... 由于环境的污染使空气中有泥土,太阳能电池在户外使用一段时间后,其窗口表面就会附着一些灰尘颗粒影响其进光量,进而影响太阳能电池的光电转换效率。采用溶胶凝胶法制备并通过热烧结过程,将Nano-SiC透明薄膜制备在太阳能电池窗口表面。通过实验测试了表面制备不同厚度的Nano-SiC薄膜对太阳能电池I-V特性的影响。实验结果表明Nano-SiC薄膜具有很好的光子透过性和自洁能力,能够提高太阳能电池的光电转换效率。 展开更多
关键词 nano-sic薄膜 太阳能电池窗口 光电转换效率 I-V特性
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45#钢表面Ni-P-nano-SiC复合化学镀层的制备 被引量:1
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作者 陈岁元 范红 +1 位作者 梁京 刘常升 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2011年第6期810-813,825,共5页
在优化设计的化学镀基础镀液中通过添加不同含量的纳米SiC颗粒,研究在45#钢表面制备具有纳米SiC颗粒增强的复合镀层及形成机理.利用SEM,XRD和显微硬度计等方法对实验样品的组织结构、形貌、显微硬度及其镀层形成机理进行了研究,结果表明... 在优化设计的化学镀基础镀液中通过添加不同含量的纳米SiC颗粒,研究在45#钢表面制备具有纳米SiC颗粒增强的复合镀层及形成机理.利用SEM,XRD和显微硬度计等方法对实验样品的组织结构、形貌、显微硬度及其镀层形成机理进行了研究,结果表明:实验制备的Ni-P,Ni-P-SiC镀层镀态时硬度分别为572 HV,649 HV,热处理后其表面硬度在400℃时达到最大值1 045 HV和1 341 HV.纳米SiC颗粒在镀液中不参与化学反应,只是与化学反应所产生的Ni和P共同沉积在镀层中起到了复合强化的作用.Ni-P-nano-SiC镀层的生长机理是按层状方式生长,生长方向垂直于钢基体表面.纳米SiC提高了复合化学镀层的生长速度,促进了复合镀层以较薄的分层方式生长. 展开更多
关键词 化学复合镀 Ni-p-nano-sic复合镀层 纳米颗粒复合强化 层状生长
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ZrO_2增韧Al_2O_3/SiC nano复合陶瓷的力学性能及微结构 被引量:1
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作者 侯耀永 蔺玉胜 +1 位作者 屈转航 李理 《现代技术陶瓷》 CAS 1997年第3期3-8,共6页
本文对Al_2O_3/SiC nano+ZrO_2(3Y)复相陶瓷的力学性能和微结构进行了研究,探讨了ZrO_2(t)应力诱导相交增韧机制和纳米粒子增韧机制相互迭加的可能性。结果表明:适量的第二相纳米粒子ZrO_2(3Y)加入对材料的微结构有很大影响,同时对材料... 本文对Al_2O_3/SiC nano+ZrO_2(3Y)复相陶瓷的力学性能和微结构进行了研究,探讨了ZrO_2(t)应力诱导相交增韧机制和纳米粒子增韧机制相互迭加的可能性。结果表明:适量的第二相纳米粒子ZrO_2(3Y)加入对材料的微结构有很大影响,同时对材料的力学性能的提高作出贡献。 展开更多
关键词 陶瓷 力学性能 微结构 增韧 复合陶瓷
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硅烷偶联剂改性CE/nano-SiC静态力学性能的研究
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作者 张学英 张文根 +2 位作者 祝保林 王君龙 梁国正 《塑料》 CAS CSCD 北大核心 2009年第1期77-79,共3页
采用模塑成型法制备CE/nano-S iC复合材料,分别考察了3种偶联剂表面处理nano-S iC后对其静态力学性能的影响,用透射电子显微镜(TEM)表征了材料的微观结构和形貌特征。结果表明:3种偶联剂的改性效果次序为:KH-560<SCA-3<SEA-171;当... 采用模塑成型法制备CE/nano-S iC复合材料,分别考察了3种偶联剂表面处理nano-S iC后对其静态力学性能的影响,用透射电子显微镜(TEM)表征了材料的微观结构和形貌特征。结果表明:3种偶联剂的改性效果次序为:KH-560<SCA-3<SEA-171;当nano-S iC含量为1.00%时,相对于纯CE的冲击强度和弯曲强度,SEA-171的提高率分别为95.06%和34.69%。 展开更多
关键词 氰酸酯树脂 偶联剂 nano-sic 力学性能 复合材料
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KH-560改性CE/nano-SiC复合材料的韧性和耐热性
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作者 张学英 张文根 +2 位作者 祝保林 王君龙 梁国正 《材料开发与应用》 CAS 2009年第1期1-3,共3页
采用模塑成型法制备CE/nano-SiC复合材料,通过冲击强度测试、TGA分析和DMA分析,发现偶联剂KH-560表面处理nano-SiC后,对其韧性和耐热性具有显著的协同改性作用。相对纯CE,经KH-560表面处理后的CE、1.00%nano-SiC复合材料,冲击强度提高86... 采用模塑成型法制备CE/nano-SiC复合材料,通过冲击强度测试、TGA分析和DMA分析,发现偶联剂KH-560表面处理nano-SiC后,对其韧性和耐热性具有显著的协同改性作用。相对纯CE,经KH-560表面处理后的CE、1.00%nano-SiC复合材料,冲击强度提高86.26%;玻璃化转变温度提高16.71%;失重5%时,热分解温度提高17.25%;450℃时,质量保持率提高59.67%。 展开更多
关键词 氰酸酯树脂 偶联剂 nano-sic 改性研究
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Nano-SiC薄膜对太阳能电板转换效率影响的研究 被引量:1
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作者 陈旭涛 张秀霞 +4 位作者 王二垒 杨小聪 娄秀丽 温俊霞 江道节 《科学技术与工程》 北大核心 2014年第11期194-195,205,共3页
采用丝网印刷法在太阳能电板超白玻璃表面制备出不同厚度的Nano-SiC薄膜,研究了Nano-SiC薄膜厚度对光子透过率和户外太阳能电板转换效率的影响。结果表明,经过两层Nano-SiC薄膜处理后,超白玻璃的平均光子透过率提高了12%左右;同时Nano-... 采用丝网印刷法在太阳能电板超白玻璃表面制备出不同厚度的Nano-SiC薄膜,研究了Nano-SiC薄膜厚度对光子透过率和户外太阳能电板转换效率的影响。结果表明,经过两层Nano-SiC薄膜处理后,超白玻璃的平均光子透过率提高了12%左右;同时Nano-SiC薄膜可以降低户外太阳能电板转换效率的降低速率,经过两层Nano-SiC薄膜处理后太阳能电板的转换效率降低速率约为未处理时的0.3倍。 展开更多
关键词 丝网印刷 nanosic薄膜 光子透过率 转换效率
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Characterization of cast A356 alloy reinforced with nano SiC composites 被引量:14
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作者 Ali MAZAHERY Mohsen Ostad SHABANI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期275-280,共6页
The microstructure and mechanical properties of nano composites processed via stir casting were studied. The composites were based on the A356 aluminum alloy reinforced with nano SiC particles. The density measurement... The microstructure and mechanical properties of nano composites processed via stir casting were studied. The composites were based on the A356 aluminum alloy reinforced with nano SiC particles. The density measurements show that the samples contain little porosity and the amount of porosity in the composites increases with increasing volume fraction of SiC. The microstructures of the composites were examined using optical microscope and transmission electron microscope. Microscopic observations of the microstructures reveal that the dispersion of the particles is uniform. The yield strength, ultimate tensile strength and the elastic modulus are improved with the addition of nano particles although some reduction in ductility is observed. The highest yield strength and ultimate tensile strength are obtained with the addition of 3.5% SiC nano-particles. A relatively ductile fracture in tensile fractured samples was observed by fractography examination. 展开更多
关键词 aluminum matrix composites sic STRENGTH nano
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纳米银双面烧结SiC半桥模块封装技术
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作者 张兆华 孟伟 +1 位作者 崔凯 胡永芳 《电子机械工程》 2023年第4期37-41,共5页
为满足雷达阵面高功率密度的需求,SiC宽禁带半导体器件在电源模块应用中逐步取代传统硅功率器件。传统焊接及导电胶粘工艺存在导电性能差、热阻大、高温蠕变等缺点,无法发挥SiC功率器件高结温和高功率的优势。纳米银烧结是大功率器件最... 为满足雷达阵面高功率密度的需求,SiC宽禁带半导体器件在电源模块应用中逐步取代传统硅功率器件。传统焊接及导电胶粘工艺存在导电性能差、热阻大、高温蠕变等缺点,无法发挥SiC功率器件高结温和高功率的优势。纳米银烧结是大功率器件最合适的界面互连技术之一,具有低温烧结高温使用的优点和良好的高温工作特性。文中针对高功率电源模块大电流传输对低压降及高效散热的需求,基于高功率半桥电源模块开展了SiC芯片的纳米银双面烧结工艺技术研究,突破了成型银焊片制备、纳米银焊膏高平整度点涂、无压烧结等关键技术,并通过烧结界面微观分析以及芯片剪切强度和焊片剥离强度测试对烧结工艺参数进行了优化。最后对半桥模块进行了静态测试和双脉冲测试。该模块的栅极泄漏电流<1.5 n A,开关切换时间<125 ns,漏极电压过冲<12.5%,满足产品应用需求。 展开更多
关键词 纳米银焊膏 双面烧结 无压烧结 sic MOSFET 半桥模块
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DIELECTRIC PROPERTIES OF NANO Si/C/N COMPOSITE POWDER AND NANO SiC POWDER AT HIGH FREQUENCIES AND MICROSTRUCTURE CHARACTERIZATION 被引量:2
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作者 D.L.Zhao, H.S.Zhao and W.C.Zhou State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1999年第5期1136-1141,共6页
The dielectric properties of nano Si/C/N composite powder and nano SiC powder at high frequencies have been studied. The nano Si/C/N composite powder and nano SiC powder were synthesized from hexamethyldisilazane ((Me... The dielectric properties of nano Si/C/N composite powder and nano SiC powder at high frequencies have been studied. The nano Si/C/N composite powder and nano SiC powder were synthesized from hexamethyldisilazane ((Me 3Si) 2NH) (Me:CH 3) and SiH 4 C 2H 2 respectively by a laser induced gas phase reaction. The complex permittivities of the nano Si/C/N composite powder and nano SiC powder were measured between 8 2GHz and 12 4GHz. The real and imaginary parts of the complex permittivities of nano Si/C/N composite powder are much higher than those of nano SiC powder. The SiC microcrystalline in the nano Si/C/N composite powder dissolved a great deal of nitrogen. The local structure around Si atoms changed by introducing N into SiC. Carbon atoms around Si were substituted by N atoms. So charged defects and quasi free electrons moved in response to the electric field, diffusion or polarization current resulted from the field propagation. The high ε″and loss factor tgδ(ε″/ε′) of Si/C/N composite powder were due to the dielectric relaxation. 展开更多
关键词 nano Si/C/N composite powder nano sic powder dielectric properties MICROSTRUCTURE
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Production and mechanical properties of nano SiC particle reinforced Ti-6Al-4V matrix composite 被引量:4
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作者 G.SIVAKUMAR V.ANANTHI S.RAMANATHAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第1期82-90,共9页
Different mass fractions (0, 5%, 10%, and 15%) of the synthesized nano SiC particles reinforced Ti-6Al-4V (Ti64) alloy metal matrix composites (MMCs) were successfully fabricated by the powder metallurgy method.... Different mass fractions (0, 5%, 10%, and 15%) of the synthesized nano SiC particles reinforced Ti-6Al-4V (Ti64) alloy metal matrix composites (MMCs) were successfully fabricated by the powder metallurgy method. The effects of addition of SiC particle on the mechanical properties of the composites such as hardness and compressive strength were investigated. The optimum density (93.33%) was obtained at the compaction pressure of 6.035 MPa. Scanning electron microscopic (SEM) observations of the microstructures revealed that the wettability and the bonding force were improved in Ti64 alloy/5% nano SiCp composites. The effect of nano SiCp content in Ti64 alloy/SiCp matrix composite on phase formation was investigated by X-ray diffraction. The correlation between mechanical parameter and phase formation was analyzed. The new phase of brittle interfaced reaction formed in the 10% and 15% SiCp composite specimens and resulted in no beneficial effect on the strength and hardness. The compressive strength and hardness of Ti64 alloy/5% nano SiCp MMCs showed higher values. Hence, 5% SiCp can be considered to be the optimal replacement content for the composite. 展开更多
关键词 titanium alloy nano sic particle powder metallurgy HARDNESS compressive strength
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Capturing and storage of CO_2 by micron-nano minerals:Evidence from the nature 被引量:4
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作者 MAO Xumei TIAN Xike YU Chengyong 《Chinese Journal Of Geochemistry》 EI CAS 2011年第4期569-575,共7页
The increase of CO2 in atmosphere is a main factor leading to "greenhouse effect", which causes more and more serious global environmental problems. The reduction of CO2 is a challenge for the survival of hu... The increase of CO2 in atmosphere is a main factor leading to "greenhouse effect", which causes more and more serious global environmental problems. The reduction of CO2 is a challenge for the survival of human beings, and it is also a big technical problem. CO2 fluid-rock interaction is a key scientific problem involved in geo-logical storage. The CO2 fluid-rock interaction has a variety of multi-scale changes. Due to great differences in the quantity of surface atoms and surface energy between micron-nano-sized minerals, and ions and crystals, the speed and efficiency of CO2 fluid-rock interaction on a micron-nano scale are much higher than those on other scales. As is known from the natural world, the micron-nano structures of pores and the surface chemical modification of natural porous minerals (zeolite, diatomite, sepiolite, palygorskite, halloysite, etc.) should be further investigated, which can be used as the micron-nano -mineral porous materials with high capacity and high efficiency for capturing CO2. Through simulating the adsorption capacity and process of CO2 by minerals in the natural world, the micron-nano technology is applied to calcium- and magnesium-based minerals (olivine, pyroxene, feldspar, clay, etc.) so as to improve the activity of calcium and magnesium and enlarge the reaction contact area. In this way, the efficiency of capturing and storage of CO2 by calcium- and magnesium-based minerals can be greatly improved. These minerals can also be used as the micron-nano-mineral materials with large capacity and high efficiency for capturing and storing CO2. 展开更多
关键词 二氧化碳排放量 纳米尺度 矿物质 微米 储存 捕获 纳米矿物材料 证据
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Effects of Ni catalyzer on growth velocity and morphology of SiC nano-fibers 被引量:2
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作者 徐先锋 肖鹏 +1 位作者 熊翔 黄伯云 《中国有色金属学会会刊:英文版》 EI CSCD 2009年第5期1146-1150,共5页
Composite felts reinforced by both SiC nano-fibers(SiC-NFs)and carbon fibers were prepared at 1 273 K using Ni granules as catalyzers with different deposition time.SiC-NFs were deposited on the surface of the carbon ... Composite felts reinforced by both SiC nano-fibers(SiC-NFs)and carbon fibers were prepared at 1 273 K using Ni granules as catalyzers with different deposition time.SiC-NFs were deposited on the surface of the carbon fibers in situ by catalytic chemical vapor deposition(CCVD).The phase,microstructure and morphology of the fibers after electroplating and deposition were characterized by XRD,SEM and TEM.The results show that the SiC-NFs produced by CCVD are composed of single crystal of β-SiC.It is found that smaller nano-granules are more active as catalyzers.The resulting SiC-NFs appear more spindle-like and have a more homogeneous dispersion.The mass change of the samples before and after deposition shows that using more Ni granules results in a faster growth velocity of SiC-NFs.With the same electroplating time,the growth velocity of the SiC-NFs first increases and then decreases.At around 4 h,it reaches the maximum growth velocity,and it becomes nearly constant at around 8 h.After 8 h, the stable growth velocity of the electroplated Ni samples is faster than that of the conventional sample produced without catalyzers, because the SiC-NFs can improve the specific surface area and the activity of the surface. 展开更多
关键词 碳纤维增强 镍催化剂 生长速度 纳米纤维 sic 催化化学气相沉积 心脑血管疾病 沉积时间
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Al_2O_3-Coated Nano-SiC Particles Reinforced Al_2O_3 Matrix Composites 被引量:2
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作者 Juxian ZHANG, Jinjun FENG and Longqiao GAOBeijing Vacuum Electronics Research Institute, PO. Box 749 Ext. Box 33, Beijing 100016, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2002年第6期541-543,共3页
Properties of Al2O3-coated nano-SiC have been compared with those of as-received SiC. The isoelectric point (IEP) of SiC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of ... Properties of Al2O3-coated nano-SiC have been compared with those of as-received SiC. The isoelectric point (IEP) of SiC changed from pH3.4 to pH7.3 after coating with the alumina precursor, which is close to that of alumina. Because both surfaces of coated SiC and AI2O3 possess higher positive charge at pH=4.5-5.0, they are uniformly dispersed in the two-phase aqueous suspensions, Then a mixed powder containing nano-SiC dispersed homogeneously into the Al2O3 matrix was achieved from flocculating the two-phase suspension. Finally, Al2O3/SiC nanocomposites were obtained by coating nano-SiC with Al2O3, in which the majority of SiC particles were located within the AI2O3 grains. The observation by transmission electron microscopy (TEM) and the analysis by the X-ray photoelectron spectroscopy (XPS) showed that cracks propagated towards the intragranular SiC rather than along grain boundaries. 展开更多
关键词 Coated nano-sic Colloidal processing nanoCOMPOSITES Intragranular structure Transgranular fracture
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